QTL Identification Of Booting Stage Related Character And Yield Traits Under Salt Stress In Rice

Rice is one of the most important grain crops in china. Rice production has a very importantposition in China. However, with the development of global industrialization, the lack of fresh waterresources, soil salinization area increased. Soil salinization is one of the most important abiotic factorslimiting rice production safety and development.It is of great significance to carry out the research ofsalt tolerance in rice. In this study, F_2:3population derived from the cross between Changbai10andDongnong425were used as the experimental materials to construct the genetic linkage map and detectQTLs controlled the sword leaves traits and Na⁺、K⁺content in rice plant and the final yield traits undersalt stress and conventional cultivation conditions, in order to provide a theoretical basis for rice salttolerance breeding and molecular marker assisted breeding. The main results of this study are asfollows:1. A molecular linkage map was constructed based on123SSR markers.This linkage map was atotal of1616.53cM in length with an average marker interval of13.14cM.2. All the16examined traits of F3population under two cultivating conditions followed a normaldistribution. Transgressive inheritance of F3population was obvious.3. In two kinds of cultivation conditions, leaf traits were highly significant positive correlation.Under salt stress, sword leaves length and sword leaf area were highly significantly and positivelycorrelated with empty grain number per spike, total grain number per spike and percentage of empty;empty grain number per spike and percentage of empty were highly significantly and positivelycorrelated with Na⁺content in roots; Under conventional cultivation conditions, sword leaves width andsword leaf area were highly significantly and positively correlated with total grain number per spike,thousand-grain weight and ears weight; Empty grain number per spike were highly significantly andpositively correlated with percentage of empty and total grain number per spike; Total grain number perspike were highly significantly and positively correlated with ears weight.4.Using the composite interval mapping method, we identified QTLs for sword leaveslength,sword leaves wide, sword leaves area,leaf rolling index, empty grain number per spike, totalgrain number per spike, percentage of empty, content of rice plants Na⁺and K⁺, thousand-grain weight,ears weight and effective ears under two cultivating conditions. The results were as follows:（1） Six QTLs for SLl were detected. Among them, three were located on chromosome2、6、7undersalt stress, three were located on chromosome4、7、12under common condition.（2） Seven QTLs for SLW were detected. Four were located on chromosome4、7、8、10under saltstress, three were located on chromosome2and12under common condition. （3） Seven QTLs for SLA were detected. Four were located on chromosome2、3、4、6under saltstress, three were located on chromosome2and12under common condition.（4） Tow QTLs for LRI were detected, which were located on chromosome2、7under salt stress.（5） Seven QTLs for ACR were detected. Four were located on chromosome2、5、8、10under saltstress, three were located on chromosome3、7、8under common condition.（6） Six QTLs for ACL were detected. Three were located on chromosome7、8、12under salt stress,three were located on chromosome3and7under common condition.（7） Four QTLs for ACS were detected. Three were located on chromosome1、6、7under salt stress,one were located on chromosome8under common condition.（8） Eight QTLs for KCR were detected. Four were located on chromosome3、5、6、11under saltstress, four were located on chromosome3、5、8under common condition.（9） Nine QTLs for KCL were detected. Four were located on chromosome3、7、8under salt stress,five were located on chromosome1、3、5、11under common condition.（10） Eight QTLs for KCS were detected. Tow were located on chromosome3、7under salt stress,six were located on chromosome1、7、10、12under common condition.（11） Fourteen QTLs for ENP were detected. Six were located on chromosome1、3、8、11、12undersalt stress, eight were located on chromosome2、3、8、12under common condition.（12） Eight QTLs for TNS were detected. Three were located on chromosome3、6、12under saltstress, five were located on chromosome1、3、7、8、12under common condition.（13） Eleven QTLs for PE were detected. Five were located on chromosome1、5、7、12under saltstress, six were located on chromosome3、8、12under common condition.（14） Eight QTLs for TW were detected. Six were located on chromosome1、3、5、8、10under saltstress, tow were located on chromosome7、8under common condition.（15） Four QTLs for EE were detected. Tow were located on chromosome6under salt stress, towwere located on chromosome7、10under common condition.（16） Six QTLs for EW were detected. Three were located on chromosome2、12under salt stress,three were located on chromosome2、12under common condition.